Linux Daily notes 3

I. Administrative authority and attribution

1. Overview of permissions

Document attribution

Owner (U): The user who owns this file/directory-user

Owning Group (g): The group that owns this file/directory-group

Other users (O): Users other than the owner, the owning group-other

Access rights

Read (R): Allow viewing of content-read

Write (W): Allow content to be modified-write

Executable (x): Allow to run and switch-excute

2. View Permissions Ls-l

# ls-l/ETC/PASSWD

-|rw-|r--|r--. 1 root root 2481 February 09:37/etc/passwd

①②③④⑤⑥⑦⑧⑨⑩

Permission reading order: ⑩①⑥②⑦③④

① File types

- Documents

Catalog D

L Link

② Owner's permissions

R = 4 Read

w = 2 Write

x = 1 executable

- No

③ permissions of the owning group

R = 4 Read

w = 2 Write

x = 1 executable

- No

④ Permissions for other users

R = 4 Read

w = 2 Write

x = 1 executable

- No

⑤ Number of links

Files: Number of links

Directory: How many subdirectories are in this directory (. .. ）

⑥ owner

⑦ belongs to Group

⑧ File Size

⑨ File creation time

⑩ File/directory Name

3. Change file Attribution

# chown Master: File/directory Change the owner of a file/directory

# chown: Group file/directory Change the owning group of file/directory

# chown: Genus group File/directory Change the owner and owning group of files/directories

- R recursion

eg

[Email protected] ~]# rm-rf/tmp/*

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# Mkdir/tmp/studir

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# chown student/tmp/studir/

[[email protected] ~]# ID Student

[Email protected] ~]# Useradd student

[[email protected] ~]# ID Student

[Email protected]td1711 ~]# chown student/tmp/studir/

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# chown:users/tmp/studir/

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# chown root:root/tmp/studir/

[Email protected] ~]# Ls-ld/tmp/studir

4. Change file/directory permissions

chmod command

Format: chmod [ugoa][+-=][rwx] Document Path ...

-R: Recursive modification (with documents in all subdirectories and subdirectories)

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# chmod g-rx,o-rx/tmp/studir/

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# chmod u-w,g=rx/tmp/studir/

[Email protected] ~]# Ls-ld/tmp/studir

[Email protected] ~]# chmod a=rwx/tmp/studir/

[Email protected] ~]# Ls-ld/tmp/studir

Second, backup and recovery

1. Make/Release Zip package

A. Compress zip

Format: Zip [-ry] backup file. zip document Path ...

eg

[Email protected] ~]# ls-ld/boot/

[Email protected] ~]# ls/opt/

[Email protected] ~]# zip-ry/opt/boot_bak.zip/boot/

[Email protected] ~]# ls/opt

B. Unzip

Format: Unzip backup file. zip [-D destination Folder]

Format: Unzip backup file. zip

eg

[Email protected] ~]# Ls/tmp/todir

[Email protected] ~]# unzip-d/tmp/todir/opt/boot_bak.zip

[Email protected] ~]# Ls/tmp/todir

2. Make/release. Tar Package

A. Make a. Tar package and compress

Basic usage

Format: TAR-ZCPF backup file. tar.gz Document Path ...

Format: TAR-JCPF backup file. tar.bz2 Document Path ...

Format: TAR-JCPF backup file. Tar.xz Document Path ...

eg

[Email protected] ~]# ls-ld/var/log/

[Email protected] ~]# du-sh/var/log/

[Email protected] ~]# mkdir-p/tmp/day03

[Email protected] ~]# tar-zcpf/tmp/day03/log.tar.gz/var/log/

[Email protected] ~]# tar-jcpf/tmp/day03/log.tar.bz2/var/log/

[Email protected] ~]# tar-jcpf/tmp/day03/log.tar.xz/var/log/

[Email protected] ~]# du-sh/tmp/day03/*

B. Unzip the. Tar Package

Basic usage

Format: TAR-XPF backup file. tar.gz

Format: tar-xf backup file. tar.bz2

Format: tar-xf backup file. tar.xz [-C destination Folder]

eg

[Email protected] ~]# cd/tmp/day03/

[[email protected] day03]# ls

[Email protected] day03]# TAR-XF log.tar.gz

[[email protected] day03]# ls

[Email protected] day03]# RM-RF var

[[email protected] day03]# ls

[Email protected] day03]# TAR-XF log.tar.bz2

[[email protected] day03]# ls

[Email protected] day03]# RM-RF var

[[email protected] day03]# ls

[Email protected] day03]# TAR-XF LOG.TAR.XZ

[[email protected] day03]# ls

[Email protected] day03]# RM-RF var

[[email protected] day03]# ls

Third, access to the CD and ISO image

1. Mounting

Mount device mount point (must be a directory)

2. Uninstall

Umount Equipment

Umount mount point

Optical drive device under 3.Linux

/dev/sr0

/dev/cdrom

Experiment: Accessing a disc file

1. Insert the disc

Put the ISO file into the optical drive

2. Mounting

[Email protected] ~]# Ls/mnt/dvd

[Email protected] ~]# mkdir-p/mnt/dvd

[Email protected] ~]# ls/mnt/dvd/

[Email protected] ~]# mount/dev/cdrom/mnt/dvd/

3. Accessing CD Contents

[Email protected] ~]# ls/mnt/dvd/

4. Uninstall

[Email protected] ~]# Umount/mnt/dvd

[Email protected] ~]# ls/mnt/dvd/

Linux Daily notes 3